The present invention relates to a controller, and more particularly, to an engine start controller provided with a smart ignition function.
In recent years, engine start/stop control systems provided with a “smart ignition” function for controlling starting and stopping of an engine have been proposed to improve the operability of vehicles. Japanese Laid-Open Patent Publication No. 2002-317689 describes an example of such an engine start/stop control system. In this engine start/stop control system, when an owner (driver) carrying a portable device enters a passenger compartment of a vehicle, the portable device automatically communicates with an engine start controller installed in the vehicle. When the communication authenticates that an ID of the portable device corresponds to an ID of the vehicle, the engine start controller permits starting of the engine.
To prevent vehicle thefts, the vehicle has a steering lock mechanism. The steering lock mechanism prevents the vehicle from being stolen by restricting rotation of the steering shaft while the vehicle is parked. In the engine start/stop control system, the ID of the portable device is first authenticated through communication. Afterwards, the steering shaft is unlocked when the driver operates an operation switch, such as a push switch, arranged in the vicinity of the driver's seat in the vehicle.
The engine start controller switches power supply modes when the operation switch is operated. To be more specific, the engine start controller switches the power supply mode to one of a mode for supplying power to an accessory (ACC) system including electric components such as a car audio system (hereafter referred to as the “ACC system power supply mode”), a mode for supplying power to, in addition to the electric components, an ignition-on (IG-ON) system including the air conditioner and gauges in the instrument panel (hereafter referred to as the “IG-ON system power supply mode”), and a mode for cutting the supply of power to any of these electric device systems (hereafter referred to as the “power OFF mode”).
For example, when the driver starts the engine using a mechanical key, the power supply mode is switched in the following way. First, the driver inserts the mechanical key in a key cylinder and turns the mechanical key. Then, the engine start controller unlocks the steering shaft and supplies power to the ACC system. Afterwards, when the driver further turns the mechanical key, the engine start controller supplies power to the IG-ON system. In this way, when the driver starts the engine with the mechanical key, the steering shaft is first unlocked. Afterwards, power is supplied to the ACC system and then to the IG-ON system. With reference to FIG. 1, the following describes the procedures performed by a conventional engine start controller in which the operation switch is operated, the system to which power is supplied (power supply system) is switched, and the engine is started. In FIG. 1, the rectangular blocks represent processes that require an operation of a user (driver) to proceed to the next process. The rectangular blocks with rounded corners represent processes that do not require an operation of a user (driver) to proceed to the next process.
In step J50, power is not supplied to the electric device systems (power OFF mode). In step J50, the engine start controller is set in a state in which the unlocking of the steering shaft is enabled (hereafter referred to as a “standby state”) when the ID of the portable device is authenticated through communication between the portable device and the engine start controller. When the driver operates the operation switch in the standby state, the engine start controller unlocks the steering shaft (step J51). As shown in step J52, the engine start controller then determines whether the steering shaft is unlocked. When the steering shaft is unlocked, the engine start controller switches the power supply mode to the ACC system power supply mode (step J53). Afterwards, when the driver further operates the operation switch, the engine start controller switches the power supply mode to the IG-ON system power supply mode (step J54). Then, the driver depresses the brake pedal and operates the operation switch so that the engine start controller starts the engine (step J55). In this way, the engine is started only when the steering shaft is determined as being unlocked. Subsequently, the engine starts running as shown in step J56.
In step J54, when the driver operates the operation switch without depressing the brake pedal, the engine start controller does not supply power to the electric device systems (power OFF mode) (step J57). Thereafter, the engine start controller sequentially switches the power supply mode to the ACC system power supply mode (step J53), the IG-ON system power supply mode (step J54), the power OFF mode (step J57), and the ACC system power supply mode (step J53) every time the operation switch is operated. In this way, the engine start controller shifts only to the processing in one of steps J53, J54, and J57 when the brake pedal is not depressed. Thus, the driver needs to depress the brake pedal to start the engine.
In the power OFF mode in step J50, the driver depresses the brake pedal and also operates the operation switch. Then, the engine start controller unlocks the steering shaft, and determines that the steering shaft is unlocked (step J52). Afterwards, the engine start controller starts the engine (step J55) without entering the ACC system power supply mode (step J53) and the IG-ON system power supply mode (step J54). The engine start controller also starts the engine when the driver depresses the brake pedal and operates the operation switch in steps J53 (the ACC system power supply mode), J54 (the IG-ON system power supply mode), and J57 (the power OFF mode). In this way, the driver may start the engine by depressing the brake pedal and also operating the operation switch in any power supply mode.
When the driver operates the operation switch while the engine is running, the engine start controller stops the engine and switches the power supply mode to the power OFF mode (step J57).
As described above, a conventional engine start controller switches the power supply mode from the power OFF mode to the ACC system power supply mode after the steering shaft is unlocked. Thus, a long period of time is required from when the operation switch is operated to when the power supply mode is switched to the ACC system power supply mode. As a result, a long period of time is required from when the operation switch is operated to when the engine is started.